Ocular treatment devices and related methods of use

ABSTRACT

Apparatus and methods for ocular treatment are provided. The apparatus can comprise a microcannula having a proximal end, a distal end, a cavity, and a central longitudinal axis. The apparatus can include a handle coupled to the proximal end of the microcannula. The apparatus can include multiple offices extending circumferentially about the microcannula distal end, each of the orifices defining a channel extending transverse to the central longitudinal axis, and one or more grooves about a circumference of the microcannula.

RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. § 119(e)of U.S. Provisional Application No. 62/436,099, titled “OCCULARTREATMENT DEVICES AND RELATED METHODS OF USE,” and filed on Dec. 19,2016, the entirety of which is incorporated herein by reference.

TECHNICAL FIELD

Various aspects of the present disclosure relate generally to oculartissue treatment. More specifically, the present disclosure relates toinstruments and related methods for reducing intraocular eye pressure.

INTRODUCTION

Glaucoma is a disease resulting from an increase in intraocular eyepressure (TOP). IOP may increase when natural drainage of the eye (e.g.,drainage of the humus of the eye) is prevented, reduced, or otherwiseblocked. Cavities in front of (e.g., on top of) the lens of the eye arefilled with a viscous fluid called aqueous humor. A continuous flow ofaqueous humor through the eye provides nutrition to portions of the eye(e.g., the cornea and the lens) that have no blood vessels. This flow ofaqueous humor also removes waste (e.g., foreign object debris) fromthese tissues. In a healthy eye, a stream of aqueous humor drains out ofthe anterior chamber of the eye through the trabecular meshwork and intoSchlemm's canal as new aqueous humor is secreted by the epithelial cellsof the ciliary body. The drained aqueous humor enters the venous bloodstream from Schlemm's canal and is carried along with the venous bloodleaving the eye. When the natural drainage mechanisms of the eye (e.g.,Schlemm's canal and/or the trabecular meshwork) stop functioningproperly, the IOP begins to increase.

Prior treatments to reduce TOP may include application of eye drops andother medications. Application of such medications may be requiredmultiple times a day, and may interfere with a patient's quality oflife. Additionally, laser treatments and other surgical applications maybe used to reduce TOP, however, such treatments may be invasive andoften provide only temporary reduction of TOP.

The systems, devices, and methods of the current disclosure may rectifysome of the deficiencies described above or address other aspects of theprior art.

SUMMARY

At least one aspect is directed to a medical device. The medical deviceincludes a microcannula having a proximal end, a distal end, a cavity,and a central longitudinal axis. The medical device includes a handled,coupled to the proximal end of the microcannula. The microcannulaincludes multiple orifices, extending circumferentially about themicrocannula distal end. Each orifice defines a channel extendingtransverse to the central longitudinal axis, and one or more groovesabout a circumference of the microcannula.

In some implementations, an outer diameter of the microcannula variesalong a length of the microcannula.

In some implementations, an inner diameter of the microcannula variesalong a length of the microcannula.

In some implementations, a first orifice among the orifices is spaced180 degrees apart from a second orifice among the multiple of orifices.

In some implementations, each of the one or more grooves have a depthbetween 15 μm and 35 μm.

In some implementations, each of the one or more grooves are formedproximal to the orifices.

In some implementations, each of the one or more grooves is spaced apartfrom another groove by a distance between 40 μm and 60 μm.

At least one aspect is directed to a medical device that includes afirst cannula having a distal end, and a cavity, the first cannulahaving a central longitudinal axis, and protrusions. The protrusions ofthe first cannula extend circumferentially at the distal end of thefirst cannula and are located in the cavity of the first cannula. Themedical device includes a second cannula having a distal end, and acavity. The second cannula is moveably housed within the first cannulaand has a central longitudinal axis, protrusions, and a plurality oforifices extending circumferentially about the distal end of the secondcannula. The protrusions of the second cannula extend circumferentiallyat the distal end of the second cannula and are located on an outercircumferential surface of the second cannula. A first orifice among theplurality of orifices is positioned parallel to a second orifice amongthe plurality of orifices.

In some implementations, the second cannula includes one or more groovesabout a circumference of the second cannula.

In some implementations, the one or grooves of the second cannula arelocated at the distal end of the second cannula.

In some implementations, the one or more grooves are equidistantlyspaced apart.

In some implementations, each of the protrusions of the first cannulaare equidistantly spaced apart.

In some implementations, the protrusions of the second cannula areproximal to a user than the protrusions of the first cannula when thedistal end of the second cannula is within the first cannula.

In some implementations, the protrusions of the second cannula aredistal to a user than the protrusions of the second cannula when atleast a portion of the distal end of the second cannula is moved outsideof the distal end of the first cannula.

At least one aspect is directed to a method of delivering fluid into theeye. The method includes inserting a microcannula through an incision inan anterior chamber of an eye. The microcannula including a proximalend, a distal end, and a cavity, the microcannula having a centrallongitudinal axis. Advancing the microcannula distal end through atrabecular meshwork of an eye and into Schlemm's canal of an eye.Delivering fluid through a plurality of orifices each of which beingpositioned within Schlemm's canal, each orifice defining a channelextending circumferentially about the microcannula distal end.

In some implementations, the channel of the orifice of the plurality oforifices extends transverse to the central longitudinal axis.

In some implementations, the microcannula includes one or more groovesabout a circumference of the microcannula at the distal end of themicrocannula.

In some implementations, the microcannula includes one or moreprotrusions extending circumferentially at the distal end of themicrocannula and located on an outer circumferential surface of themicrocannula. The microcannula is movably housed within a secondcannula, the second cannula having one or more protrusions extendingcircumferentially at a distal end of the second cannula and located acavity of the second cannula.

In some implementations, the step of advancing the microcannula distalend further includes applying a force to the microcannula to move theone or more protrusions of the microcannula distal to a user and pastthe one or more protrusions of the second cannula.

At least one aspect is directed to a medical device. The medical deviceincludes a microcannula having a proximal end, a distal end, a cavity,and a central longitudinal axis. The medical device includes a handled,coupled to the proximal end of the microcannula. The microcannulaincludes multiple orifices, extending circumferentially about themicrocannula distal end. Each orifice defines a channel extendingtransverse to the central longitudinal axis, and one or more protrusionsabout a circumference of the microcannula.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate exemplary aspects of the presentdisclosure and together with the description, serve to explain theprinciples of the disclosure.

FIG. 1 illustrates an exemplary device having a handle and amicrocannula, according to aspects of the disclosure;

FIG. 2A is an enlarged view of a microcannula of the device of FIG. 1,according to an illustrative implementation;

FIG. 2B is an enlarged view of a microcannula of the device of FIG. 1,according to an illustrative implementation;

FIG. 2C is an enlarged view of the tip of the microcannula of FIG. 2B,according to an illustrative implementation;

FIG. 2D is an enlarged view of a fastening mechanism of the microcannulaof FIG. 2B, according to an illustrative implementation;

FIGS. 2E and 2F illustrate an exemplary device with multiple cannulas,according to an illustrative implementation;

FIGS. 2G-2J illustrate various actuators included in exemplary device,according to an illustrative implementation;

FIGS. 2K and 2L illustrate an exemplary device with an outer tube,according to an illustrative implementation;

FIGS. 2M and 2N illustrate enlarged cross-sectional views of amicrocannula and an outer sheath of the device of FIG. 1;

FIG. 3A illustrates a cross-sectional view of the exemplary device ofFIG. 1, according to an illustrative implementation;

FIG. 3B illustrates a cross-sectional view of a reservoir of theexemplary device of FIG. 1, according to an illustrative implementation;

FIG. 3C illustrates a cross-sectional view of another implementation ofthe exemplary device of FIG. 1, according to an illustrativeimplementation;

FIG. 4A illustrates a perspective view of the microcannula of the deviceof FIG. 1, according to an illustrative implementation;

FIGS. 4B-4J illustrate cross-sectional view of a tip of microcannula ofthe device of FIG. 1, according to an illustrative implementation; and

FIGS. 5A and 5B illustrate an exemplary method of using the device ofFIG. 1, according to an illustrative implementation.

DETAILED DESCRIPTION

The following detailed description is exemplary and explanatory only andis not restrictive of the features, as claimed. As used herein, theterms “comprises,” “comprising,” or other variations thereof, areintended to cover a non-exclusive inclusion such that a process, method,article, or apparatus that comprises a list of elements does not includeonly those elements, but may include other elements not expressly listedor inherent to such a process, method, article, or apparatus.Additionally, the term “exemplary” is used herein in the sense of“example,” rather than “ideal.” As used herein, the terms “about,”“substantially,” and “approximately,” indicate a range of values within+/−5% of a stated value. The term “distal” refers to a portion farthestaway from a user when introducing a device into a subject. By contrast,the term “proximal” refers to a portion closest to the user when placingthe device into the subject.

As shown in FIG. 1, an exemplary device 10 includes a handle 12 coupledto a microcannula 14 via a connector 16. For example, a proximal end 18or region of microcannula 14 is coupled to a distal end 20 or region ofhandle 12 via connector 16. Connector 16 includes a lumen 22 (FIG. 3A)extending through a reinforcement shaft or tube 24 and a connector body26. A proximal end of connector 16 may be threadably or otherwisefixedly coupled to distal end 20 of handle 12, while proximal end 18 ofmicrocannula 14 extends through lumen 22 of connector 16 and is fixedlycoupled (e.g., glued, welded, or otherwise secured) to connector 16. Insuch a manner, microcannula 14 is fixedly coupled to handle 12.

A radially outer circumferential surface of connector body 26 may beknurled, ribbed, or otherwise textured to enhance a medicalprofessional's grasp of handle 12. In some arrangements, at least one ofconnector 16 and distal end 20 includes a fluid luer port (not shown).The fluid luer port may extend radially away from connector 16 and/ordistal end 20, and may be configured for connection to interchangeableexternal reservoirs. In such a manner, a reservoir 28 (FIG. 3A)positioned within handle 12, may be selectively refilled as needed ordesired by a medical professional, as will be described in furtherdetail below.

As shown in FIG. 1, microcannula 14 includes a working length L, e.g., alength extending between a proximal end of tube 24 and a distal-most endof microcannula 14 between about 30 mm and about 40 mm. In someimplementations, working length L may be about 36.150 mm. In someimplementations, the working length L may be about 20 mm. As shown inFIG. 2A, in some implementations, a diameter D of microcannula 14 may bebetween about 500 μm and about 600 μm. A distal end 30 of microcannula14 is rounded or otherwise atraumatic (e.g., blunt, unsharpened, etc.)and includes a plurality of orifices 32. For example, distal end 30 ofmicrocannula 14 includes four orifices 32 (only two orifices 32 beingvisible in FIG. 2A) equidistantly spaced about a circumference of distalend 30. Each orifice 32 may have an orifice diameter O, between 30 μmand 70 μm. In some implementations, diameter O of each orifice 32 isabout 50 μm. In some implementations, diameter O of each orifice 32 isabout 60 μm While four equidistantly spaced orifices 32 are illustratedand described, in other arrangements, more or less orifices 32 may bepositioned about the circumference of distal end 30 and may beequidistantly or non-equidistantly spaced. For example, as shown in FIG.2B, the distal end 30 includes two orifices 32. In some implementations,orifices 32 are positioned about 180 degrees apart from each other aboutthe circumference of distal end 30, as shown in FIG. 2B (only one of thetwo orifices 32 being visible in FIG. 2B). Additionally, in somearrangements, orifices 32 may be positioned at varying axial locationsalong distal end 30. In some implementations, orifices 32 are arrangedfor delivery of a fluid (e.g., liquid or gas) or other substance from areservoir 28 (FIG. 3A) and extend at an angle non-perpendicular to acentral axis C of microcannula 14, as will be described in furtherdetail below. In some implementations, orifices 32 are arranged fordelivery of a fluid or other substance from the reservoir 28 and extendat an angle perpendicular to the central axis C of microcannula 14.

In some implementations, microcannula 14 may have an outer diameter withvarying sizes along the length of the microcannula 14. For example, asshown in FIG. 2B, outer diameter OD1 near the proximal end ofmicrocannula 14 may be between about 500 μm and about 700 μm, such asabout 600 μm, and outer diameter OD2 near the distal end of microcannula14 may be between about 100 μm and about 200 μm, such as about 150 μm.The outer diameter of microcannula 14 may taper down near a terminal endof microcannula 14. For example, in FIG. 2B, the outer diameter OD1 ofmicrocannula 14 is tapered down to OD2 near the terminal end 98 ofmicrocannula 14. A first outer diameter of microcannula 14 may taperdown starting from a certain distance away from a terminal end ofmicrocannula 14. For example, in FIG. 2B, the outer diameter OD1 may betapered down starting from 350 μm away from the terminal end 98 ofmicrocannula 14. A first outer diameter of microcannula 14 may begradually tapered down to a second outer diameter. For example, in FIG.2B, starting from 350 μm away from the terminal end 98 of microcannula14, the outer diameter OD1 is tapered down gradually from 600 μm to theouter diameter OD2 of 150 μm near the terminal end 98.

Microcannula 14 may have an inner diameter with varying sizes along thelength of the microcannula 14. For example, an inner diameter near theproximal end of microcannula 14 may be between about 300 μm and 500 μm,such as 400 μm, and an inner diameter near the distal end of themicrocannula 14 may be of a different size than the inner diameter nearthe proximal end. In some implementations, the inner diameter ofmicrocannula 14 may be tapered down from the inner diameter near theproximal end to the inner diameter near the distal end starting from acertain distance away from the terminal end of microcannula 14. In someimplementations, the inner diameter of microcannula 14 may be tapereddown starting from the location of a circumferential groove on themicrocannula 14, for example, a circumferential groove closest to theproximal end of microcannula 14, such as circumferential groove 99 a inFIG. 2B. In some implementations, the inner diameter of microcannula 14is tapered down at the same rate as the outer diameter of microcannula14 is tapered down, such that the ratio between the size of the outerdiameter and the size of the inner diameter is constant or nearconstant. In some implementations, inner diameter of microcannula 14 istapered down starting from the same location on the microcannula 14 asouter diameter of microcannula 14 is tapered down. For example, asdescribed above, outer diameter of microcannula 14 may be tapered downfrom OD1 starting from a location on microcannula 14 that is 350 μm awayfrom terminal end 98 of microcannula 14, and similarly, inner diameterof microcannula 14 may be tapered down from a first size starting from alocation that is 350 μm away from the terminal end 98 of microcannula14.

Microcannula 14 may include one or more grooves about the circumferenceof microcannula 14 (referred to herein as “circumferential grooves”),such as circumferential grooves 99 a, 99 b, 99 c. In someimplementations, as shown in FIG. 2B and FIG. 2C, microcannula 14include three such circumferential grooves. Each circumferential groovemay be spaced apart from another circumferential groove on microcannula14 by a distance gd, as shown in FIG. 2B. The distance gd may be betweenabout 40 μm and about 60 μm. For example, the distance gd betweencircumferential grooves 99 a, 99 b, and 99 c in FIG. 2B may be about 50μm. Each circumferential groove may be of depth gDe, as shown in FIG.2C. The depth gDe may be between about 15 μm and 35 μm. In someimplementations, circumferential grooves have depth gDe of 25 μm. Asshown in FIG. 2B, circumferential grooves may be formed near the distalend of microcannula 14. In some implementations, circumferential groovesmay be formed starting from a location on microcannula 14 that isbetween about about 500 μm away and 250 μm away from the terminal end 98of microcannula 14, for example, starting from about 350 μm away fromthe terminal end 98 of microcannula 14. In some implementations, thedistal portion of the microcannula 14, starting from a location onmicrocannula 14 that is between about 500 μm away and 250 μm away fromterminal end 98 of microcannula 14, is configured to be a rough shaft.

In some implementations, microcannula 14 may include one or moreprotrusions about the circumference of microcannula 14 (referred toherein as “circumferential protrusions”). Each circumferentialprotrusion may be spaced apart from another circumferential protrusionon microcannula 14 by a certain distance, such as a distance betweenabout 40 μm and about 60 μm. In some implementations, eachcircumferential protrusion may be about 50 μm. Each circumferentialprotrusion may be of a certain height between about 15 μm and 35 μm. Insome implementations, circumferential protrusions have height of 25 μm.Circumferential protrusions may be formed near the distal end ofmicrocannula 14. In some implementations, circumferential protrusionsmay be formed starting from a location on microcannula 14 that isbetween about about 500 μm away and 250 μm away from the terminal end 98of microcannula 14, for example, starting from about 350 μm away fromthe terminal end 98 of microcannula 14. Microcannula 14 may be formed ofvarious materials including, but not limited to, polymethyl methacrylate(PMMA), polyimide, various types of silicones, such as high durometersilicone, and the like. Microcannula 14 may include or be coupled to afastening mechanism. An example of such a fastening mechanism is a luerlock, such as luer lock 102, shown in FIG. 2D. In some implementations,the fastening mechanism may be configured with an external threadprofile, such as the external thread profile 103 of luer lock 102 shownin FIG. 2D. In some implementations, microcannula 14 is attached orcoupled to a fastening mechanism, such as a luer lock 102, at theproximal end of microcannula 14. In some implementations, connector body26 may be configured to accept the fastening mechanism. For example, ifthe fastening mechanism includes an external thread profile, connectorbody 26 may be configured with an internal thread profile (not shown)near the distal end of connector body 26 to accept the fasteningmechanism.

In some implementations, exemplary device 10 may include multiplecannula and/or microcannula, such as outer cannula 210, inner cannula230, as shown in FIG. 2E. Inner cannula 230 may be housed within outercannula, as shown in FIG. 2E. In FIG. 2E, outer cannula 210 may have anouter diameter between 200 and 400 μm, such as about 250 μm, 300 μm, or350 μm. In some implementations, outer cannula 210 has an inner diameterbetween 100 μm and 200 μm. Outer cannula 210 includes one or moreprotrusions, such as protrusions 220 a, 220 b, collectively protrusions220. Protrusions 220 are located on the inside of the outer cannula 210,such as on the inner circumferential surface of the outer cannula 210.Protrusions 220 may be equidistantly or non-equidistantly spaced apartfrom each other. Protrusions 220 may be protruding notches, extensions,and the like. In some implementations, protrusions 220 extend towardseach other. Outer cannula 210 is coupled to a distal end of handle 12,such as distal end 20 via connector 16. As described above, innercannula 230 is housed within outer cannula 210. Inner cannula 230 isalso housed within handle 12 and is configured to extend out from handle12 and retract into handle 12. A control unit, such as actuator 38, isconfigured to control the extension and retraction of inner cannula 230.

Inner cannula 230 includes one or more protrusions, such as protrusions240 a, 240 b, collectively referred to herein as protrusions 240, asshown in FIG. 2E. Protrusions 240 may be equidistantly ornon-equidistantly spaced apart from each other and located on the outercircumferential surface of inner cannula 230. Protrusions 240 may belocated on the inner cannula 230 at locations that align withprotrusions 220 such that protrusions 220 engage protrusions 240 wheninner cannula 230 is extended out a certain distance from distal end ofhandle 12, such as distal end 20, and prevent inner cannula 230 fromextending any further until a threshold amount of force is applied to anactuator to further extend the inner cannula 230. Application ofthreshold amount of force to the actuator extends the inner cannula 230by causing protrusions 240 to depress protrusions 220. Protrusions 220may be configured to be depressed into the outer cannula 210.Application of the threshold amount of force causes the inner cannula230 to quickly penetrate trabecular meshwork 86, as shown in FIG. 2F. Insome implementations, inner cannula 230 may include circumferentialgrooves, such as circumferential grooves 99 a, 99 b, and 99 c, as shownin FIG. 2B. In some implementations, inner cannula 230 may include oneor more orifices, such as orifices 32, positioned about thecircumference of a distal end of inner cannula 230. The orifices ofinner cannula 230 may be equidistantly or non-equidistantly spaced. Insome implementations, orifices of inner cannula 230 are positioned about180 degrees apart from each other about the circumference of distal endof inner cannula 230, similar to position of orifices 32, describedabove, and as shown in FIG. 2B. In some implementations, orifices ofinner cannula 230 may be positioned at varying axial locations alongdistal end of inner cannula 230 and orifices of inner cannula 230 arearranged for delivery of a fluid (e.g., liquid or gas) or othersubstance from a reservoir, such as reservoir 28, as shown in FIG. 3A.In some implementations, the orifices of inner cannula 230 extend at anangle non-perpendicular or transverse to a central axis of inner cannula230.

Handle 12 may have an ergonomic shape designed to be held comfortably inthe hand, e.g., the palm of the dominate hand of a medical professional.Handle 12 may have a length between about 5 inches (12.7 cm) and about10 inches (25.4 cm) Handle 12 may include a proximal end 34, distal end20, and a channel or track 36 extending there between, as will bedescried in further detail below. Proximal end 34 and distal end 20 havea generally circular cross-sectional shape. Alternatively, proximal end34 and distal end 20 may have any other cross-sectional shape (e.g.,oval, polygonal, irregular, etc.) without departing from the scope ofthis disclosure. In some arrangements, the cross-sectional shape ofproximal end 34 and/or distal end 20 may vary along the length of handle12 and/or be different from each other. Optionally, proximal end 34 maybe tapered or narrowed in a proximal direction, as shown.

Handle 12 includes an actuator 38. Actuator 38 includes a button orslide 40 received within track 36 of handle 12. In some arrangements,slide 40 may be at least partially bent or folded, as shown in FIGS. 1and 3. Alternatively, slide 40 may have any appropriate shape. A firstend 42 (e.g., a distal end) of slide 40 may be fixedly (e.g.,permanently fixed, non-separable, fixed throughout use, welded, glued,and/or heat staked, etc.) to a sled, carriage, and/or actuator body 44movably positioned (e.g., slidably, translatable, etc.) within handle12. For example, actuator body 44 may move, slide, or translate along anaxis (e.g., a central longitudinal axis of handle 12 or an axis parallelthereto) with respect to handle 12, as will be described in furtherdetail below. Additionally, a second end 46 (e.g., proximal end) ofslide 40 includes a protrusion or projection sized to be received withintrack 36, as will be described in further detail below. As shown, secondend 46 is angled, tapered, or slanted to facilitate movement along track36, as will be described in further detail below. In someimplementations, actuator 38 may be a push button, such as push button250, as shown in FIG. 2G, a scroll wheel 251, as shown in FIG. 2H, aslider 252, as shown in FIG. 2I and the like. In some implementations,actuator 38 may be configured to be squeezed, such as actuator 253, asshown in FIG. 2J, to control delivery of fluid via microcannula 14.

In some implementations, microcannula 14 is housed within an outer tube,such as outer tube 254, as shown in FIG. 2K. The outer tube 254 includesan opening or cut out such as opening 255. In some implementations, theopening or cutout 255 is located at the distal end of outer tube 254, asshown in FIG. 2K. The outer tube 254 extends to the handle 12 and isconfigured to be rotated by a control mechanism located proximal to thehandle 12. Rotating the outer tube 254 may expose or hide one or moreorifices on the microcannula 14, such as orifices 32 at the distal end.For example, as shown in FIG. 2L, rotating the outer tube 254, such thatthe opening 255 is moved from the position in FIG. 2K to the position inFIG. 2L, the orifices 32 exposed in FIG. 2K are now hidden in FIG. 2L.

In some implementations, microcannula 14 is movably housed within anouter sheath, such as outer sheath 260, as shown in FIG. 2M.Microcannula 14 is configured to extend out of a distal end of outersheath 260 in response to a user interaction with a control mechanismconfigured to extend and retract at least a portion of microcannula 14,such as the tip of microcannula 14, out of and in to outer sheath 260,respectively. For example, a user may apply a threshold amount of forceto an actuator coupled to the microcannula 14, in the directionconfigured to cause the microcannula 14 to extend outside of the outersheath 260, in order to extend the microcannula 14 outside of the outersheath 260, as shown in FIG. 2N. In some implementations, the outersheath 260 is configured to move in the direction proximal to a user ofmedical device 10 causing at least a portion of the microcannula 14,such as the tip of the microcannula 14, to be exposed outside of theouter sheath 260, as shown in FIG. 2N. The outer sheath 260 may move inthe direction proximal to the user in response to pressing the distalportion of the outer sheath 260 against the trabecular meshwork of apatient.

The application of the threshold amount of force to an actuator coupledto the microcannula 14, causing at least a portion of the microcannula14 to extend outside of the outer sheath 260, causes at least thatportion of the microcannula 14 to penetrate the trabecular meshwork of apatient, such as trabecular meshwork 86 (shown in FIGS. 5A and 5B), whenthe microcannula 14 is advanced near the trabecular meshwork of thepatient. Similarly, in implementations where the outer sheath 260 isconfigured to move in the direction proximal to a user of the medicaldevice 10 in response to pressing the distal portion of the outer sheath260 against the trabecular meshwork, the exposed portion of themicrocannula 14 or a portion of the exposed portion of the microcannula14 may penetrate the trabecular meshwork.

Track 36 extends through a radially outer wall of handle 12 with respectto the central longitudinal axis of handle 12. Accordingly, slide 40 mayextend radially outwardly of the center axis through track 36. As shown,track 36 may be notched such that pairs of inwardly protruding notches,extensions, or flanges 48 extend towards each other to narrow a width oftrack 36 at a plurality of axially spaced locations along the length oftrack 36. In other words, track 36 extends longitudinally along handle12 and has a width, extending in a direction perpendicular thelongitudinal length of track 36. The width of track 36 varies along thelength of the track 36 such that each location of track 36 having a pairof flanges 48 has a smaller or more narrow width than a width of track36 at a location devoid of one or more flanges 48. An axial spacingbetween adjacent pairs of flanges 48 may directly correlate to an amountof a single dose or quantity of a substance (e.g., a fluid or gas) forinjection via microcannula 14, as will be described in further detailbelow. Additionally, it is understood that slide 40 may be replaced withany appropriate actuator, e.g., wheel, button, toggle, or the like,without departing from the scope of this disclosure.

Turning to FIGS. 3A and 4A, as noted above, connector 16 facilitatescoupling between microcannula 14 and handle 12. For example, a proximalend 50 of connector 16 may be received radially within a cavity 52 ofdistal end 20 of handle 12. Proximal end 50 and cavity 52 may becorrespondingly threaded to facilitate secure engagement therebetween.As noted above, proximal end 18 of microcannula 14 extends through lumen22 of connector 16 and may be fixedly coupled (e.g., glued, welded, orotherwise secured) to connector 16. Additionally, connector 16 includesa tube, shaft, or other such support 54 received within lumen 22 ofconnector 16, and within a lumen 56 of distal end 20 of handle 12.

A piston assembly including a piston rod 58 extends proximally through acentral lumen 60 of microcannula 14, through lumen 22 of connector 16,through lumen 56 of distal end 20 of handle 12, and towards actuatorbody 44 housed within a cavity 62 of handle 12. Piston rod 58 may bereciprocally disposed within central lumen 60. A proximal end of pistonrod 58 is fixedly coupled to actuator body 44 such that distaladvancement of actuator body 44 will result in likewise distaladvancement of piston rod 58. As shown in FIG. 4A, piston rod 58 iscoupled to a piston head 64 and is axially moveable relative to centrallumen 60 of microcannula 14. A piston passage 66 extends through pistonrod 58, through piston head 64, and terminates distally in a pistonorifice 68. A one-way or other suitable valve 70 may be arranged withinthe piston passage 66 to prevent, inhibit, or block backflow of fluid orother substances, e.g., proximally directed flow.

In order to deliver fluid or other substances from reservoir 28, amedical professional may advance slide 40 distally towards microcannula14. Due to the connection between first end 42 and actuator body 44, andthe connection between actuator body 44 and piston rod 58, distaladvancement of slide 40 advances piston head 64 towards orifices 32 todeliver fluid or other substances within central lumen 60 throughorifices 32. Any appropriate mechanism may be used to urge fluid orsubstances within reservoir 28 through the piston passage 66, throughthe one-way valve 70 within the piston passage 66, and into the cavity60. For example, reservoir 28 may be compressed thereby pushing fluid orother substances into and through the piston passage 66. Alternatively,fluid or other substances may be drawn through piston passage 66 viacapillary action, via a micro pump (e.g., a MEMS pump) or any othersuitable pump (not shown).

In some implementations, as shown in FIG. 3B, a fill port 350 may be influid communication with reservoir 28 and visco may be injected into thereservoir 28 via the fill port. A one-way valve 351 may be attached to adistal end of the reservoir 28 and a plunger 352 may be attached to aproximal end of reservoir 28. A valve spring 353 is coupled to plunger352 and one-way valve and 351. Actuation or compression of plunger 352compresses visco and opens the one-way valve 351, causing visco to ejectthrough an orifice 32 on the distal end 30 of microcannula 14. Plunger352 may be actuated mechanically or electrically. In someimplementations, plunger 352 may be actuated by a gas, such as carbondioxide, CO2. In some implementations plunger 352 may be coupled to aphaco system and actuated by the phaco system.

In some implementations, handle 12 may include a visco bag and a buttoncommunicatively coupled to the visco bag with the visco bag incommunication with an orifice 32 on the distal end 30. Depression of thebutton compresses visco bag and causes visco fluid to eject through theorifice 32 on the distal end 30. In some implementations, as shown inFIG. 3C handle 12 includes a flexible bulb 360 in communication withone-way valves 361 a, 361 b. Compression of the flexible bulb causes theone-way valves to open and visco in the handle 12 to be directed to anorifice 32 at the distal end 30.

As shown in FIG. 4A, each orifice 32 may be a channel angled relative toan axis of the microcannula 14, such as the central axis C of themicrocannula 14. As described above, an orifice 32 may extend at anangle perpendicular or non-perpendicular to an axis of the microcannula14, such that the channel is angled perpendicularly ornon-perpendicularly to the axis of the microcannula 14. In addition,each orifice may have one or more openings having a taperedconfiguration. For example, a first end (e.g., a radially inner end) ofeach orifice 32 may be positioned at a first axial location along thelength L of microcannula 14 while a second end (e.g., a radially outerend) of each orifice 32 may be positioned at a second axial locationalong the length L of microcannula 14. In some embodiments, the secondaxial location may be proximal of the first axial location. In otherembodiments, the second axial location may be distal to the first axiallocation. In such a manner, a channel defined by each orifice 32 may beangled relative to central longitudinal axis C. In other words, thefirst end of each orifice 32 is positioned radially closer to thecentral longitudinal axis C (and distally or proximally of the secondend of each orifice 32 along an axis parallel to central longitudinalaxis C), while the second end of each orifice 32 is positioned radiallyfarther away from central longitudinal axis C (and proximally ordistally of the first end of each orifice 32 along an axis parallel tocentral longitudinal axis C). For example, a channel defined by orifice32 may extend at an angle α relative to central longitudinal axis C ofbetween about 5° and about 45° degrees. Accordingly, during delivery offluid or other substance from central lumen 60 through orifices 32, thefluid or other substance will necessarily flow proximally (e.g., from adistal location towards a proximal location) or distally and radiallyaway from microcannula 14.

As noted above, axial spacing between adjacent pairs of flanges 48 oftrack 36 correlates to an amount of a single dose or quantity of fluidor other substance for injection via microcannula 14. For example,before advancement of slide 40, second end 46 of slide 40 is positionedbetween two adjacent first pairs of flanges 48, thus preventinginadvertent advancement (or retraction) of slide 40 and injection offluid or other substances through orifices 32. To advance slide 40 andinject fluid or other substances via orifices 32, a medical professionalmust first overcome the resistance provided by the two adjacent firstpairs of flanges 48 against the second end 46 of slide 40, and thencontinue advancing slide 40 to push or urge fluid or other substances incentral lumen 60 distal of piston head 64 through orifices 32. That is,as slide 40 is urged distally forward, the angled or slanted surface ofsecond end 46 will slide or move along surfaces of flanges 48 untilsecond end 46 deflects radially inwardly towards the central axis ofhandle 12 and is positioned underneath flanges 48, at which point slide40 can continue advancement distally.

As slide 40 continues distal advancement, second end 46 may be receivedbetween two adjacent second pairs of flanges 48 and retained therein,thus preventing further inadvertent advancement. For example, second end46 may deflect radially outwardly away from the central axis of handle12 (returning towards an undeflected orientation). It is understood,second end 46 may be biased radially outwardly toward the undeflectedorientation. The two second adjacent pairs of flanges 48 may be adjacent(e.g., next to) the two adjacent first pairs of flanges 48. In otherwords, as slide 40 is advanced distally, interaction between second end46 and each two adjacent pairs of flanges 48 will cause an increase ofresistance exerted to the medical professional, thereby resulting in atactile indication that a specified dose or amount of fluid or substancehas been delivered through orifices 32.

In some implementations, as shown in the exploded view of FIG. 4B, thetip of microcannula 14 includes a machined cap 401 that may be laserwelded on to the tip of microcannula 14, as shown in FIG. 4C. In someimplementations, as shown in the exploded view of FIG. 4D, wire 402 maybe adhered to the tip of the microcannula 14 using an adhesive material,such as epoxy. The resulting tip shown in FIG. 4E. In someimplementations, wire may be laser welded on to the tip of microcannula14. Tip of microcannula 14 may be encapsulated with silicone over mold403, in some implementations, as shown in FIG. 4F and in the rotatedview of FIG. 4G. The silicon overmold 403 may include one more slits 404in some implementations, as shown in FIG. 4H. In some implementations,as shown in the exploded view of FIG. 4I, polyimide overmold 406 a and406 b, and a core pin 405 may be used to encapsulate the tip of themicrocannula 14, resulting in the microcannula 14 and tip configuration,as shown in the 90 degrees rotated view of FIG. 4J. In someimplementations, tip of microcannula 14 is configured with soft polymermaterial to prevent penetration into certain portions of the patient,such as sclera. In some implementations, tip of microcannula 14 includesa light source, such as a light emitting diode, which is configured toproduce light at the trabecular meshwork in response to receiving aninput to produce light, such as powering on the light source.

In some implementations, microcannula 14 includes a nitinol (NiTi) tubeat the distal end of microcannula 14. The NiTi tube may be configured tothe The NiTi tube at the distal end is configured to one bend in acertain direction after the NiTi tube travels a certain distance. Insome implementations, handle 12 includes a control mechanism coupled tothe NiTi tube and the control mechanism is configured to rotate NiTitube 180 degrees in response to receiving an input or a user interactingwith the control mechanism.

FIGS. 5A and 5B illustrate an exemplary method of using device 10 todeliver a substance (e.g., a fluid or gas) into, e.g., Schlemm's canal80 or any other suitable portion of a patient's eye. As noted above, ina healthy eye, a stream of aqueous humor 82 drains out of the anteriorchamber 84 of the eye, through the trabecular meshwork 86 and then intoSchlemm's canal 80 and distal collector channels. The aqueous humor 82then exits through Schlemm's canal 80 into the collector channels anddistal venous system. When this flow path of aqueous humor 82 isinterrupted (e.g., due to diseased or damaged tissue in the trabecularmeshwork 86 and/or Schlemm's canal 80), the IOP of an eye may rise,potentially resulting in a variety of medical concerns (e.g., glaucoma,loss of vision, optic nerve damage, etc.). In order to improve the flowpath of aqueous humor 82, a medical professional may insert microcannula14 through an incision 88 made in the anterior chamber 84 and advancedistal end 30 of microcannula 14 through the trabecular meshwork 86 andinto Schlemm's canal 80, as shown in FIG. 5A. Optionally, distal end 30may be curved such that insertion of microcannula 14 into Schlemm'scanal 80 may be accomplished by inserting distal end 30 tangentially toSchlemm's canal 80 (e.g., in a manner similar to that of insertion of anIV needle into a vein) rather than directly pushing into Schlemm's canal80 via the distal-most end of microcannula 14.

Turning now to FIG. 5B, once distal end 30 of microcannula 14 isinserted into Schlemm's canal 80 such that each orifice 32 is fullyhoused within Schlemm's canal 80, the medical professional may inject apre-defined dose or amount of fluid or other substance from reservoir 28via actuation of slide 40 (FIGS. 1, 3A, and 4A) as discussed above.Further, since advancement of slide 40 is limited due to the interactionof second end 46 and flanges 48, each pre-defined dose or amount offluid or substance to be injected upon each incremental advancement ofslide 40 is accurate and precise. For example, each “dose” may be 200microliters+/−50 microliters.

After injection of a pre-defined dose or amount of fluid or othersubstance through orifices 32 (FIGS. 2A and 4A), microcannula 14 may berotated between about 50° and about 120°, e.g., between about 60° andabout 90° about central axis C (FIG. 4A) of microcannula 14. Oncerotated, the medical professional may inject an additional pre-defineddose or amount of fluid or other substance from reservoir 28 viaactuation of slide 40 (FIGS. 1, 3, and 4) as discussed above. Thisprocess may be repeated any appropriate number of times, e.g., about sixtimes, and then microcannula 14 may be removed from incision 88.

Optionally, after the injection of one or more pre-defined doses offluid or other substance at a certain location within Schlemm's canal 80(e.g., without relocating (other than rotating) distal end 30 ofmicrocannula 14), distal end 30 may be retracted and repositioned withinthe eye. In some arrangements, such repositioning may occur viawithdrawal of microcannula 14 from incision 88 (e.g., a first incision88), and reinsertion through an additional incision 88, spaced from thefirst incision 88. In some implementations, fluid may be delivered intothe Schlemm's canal 80 and trabecular meshwork 86 simultaneously,causing the Schlemm's canal 80 to open and deliver the fluid into thevarious layers of the trabecular meshwork 86. Alternatively, suchrepositioning may include retraction of distal end 30 from Schlemm'scanal 80 and/or trabecular meshwork 86 and then relocation into a newportion of Schlemm's canal 80 without removal of microcannula 14 fromthe first incision 88. In either case, distal end 30 of microcannula 14may be positioned approximately 30-90° away from the original insertionsite.

The substance located within reservoir 28, and injected via orifices 32may be any appropriate substance. For example, the substance maycomprise viscoelastic fluid such as, e.g., sodium hyaluronate andchondroitin sulfate. Viscoelastic fluid is a highly pliable, gel-likematerial which helps provide enough space for adequate drainage and eyepressure relief by expanding tissue structures away from one another, tore-open or expand a flow path of aqueous humor 82. Viscoelastic fluidalso may clear an obstructed view by expanding bleeding structures awayfrom one another to improve visualization.

In another arrangement, reservoir 28 may be filled with stem cells,medicaments, a gas (e.g., SF6 or C3F8), and/or dyes (e.g., trypan bluedye). Injected dye, for example, will flow through the trabecularmeshwork 86, enhancing visualization of aqueous humor 82 fluid flow todetermine which areas, if any, of the trabecular meshwork 86 remainblocked, collapsed, or otherwise impede flow of aqueous humor 82.Injected stem cells, on the other hand, may initiate growth of healthytissues within the eye (e.g., to develop healthy trabecular meshwork 86to enhance drainage of aqueous humor 82 there through).

In some arrangements, a first substance is injected into one or morelocations of the eye, the reservoir 28 is refilled with a secondsubstance different than the first substance, and then the secondsubstance is injected into one or more locations of the eye.Additionally, this process may be repeated as necessary to deliver eachselected substance. For example, as noted above one or both of connector16 and distal end 20 may include a fluid luer port (not shown), throughwhich reservoir 28 may be selectively refilled. Accordingly, a pluralityof substances, e.g., viscoelastic, medicament, stem cells, and dye, maybe injected into the eye of a patient to achieve a desired result (e.g.,visualize the flow path of aqueous humor 82, expand Schlemm's canal 80,promote tissue regrowth, or to otherwise medicinally treat diseasedtissue). Accordingly, during a procedure, a single (e.g., only one)incision 88 may be needed to deliver a variety of substances as deemednecessary and/or beneficial by the medical professional, thus reducingtrauma, recovery time, medical professional time, and associated fees,etc.

It is to be understood that while the foregoing description describesdevices and methods for injection of a fluid or other substance throughorifices 32, the disclosure is not so limited. Indeed, device 10described herein may be arranged for precision-controlled aspiration offluid or other substances away from the eye. For example, rather thandistal advancement of slide 40 to incrementally inject a pre-defined“dose” or quantity of a substance or fluid radially outwardly ofmicrocannula 14 via orifices 32, proximal retraction of slide 40 mayincrementally draw (e.g., suction, pull, etc.) fluid or other substances(e.g., tissue, blood, aqueous humor 82, etc.) out of Schlemm's canal 80for removal from the eye. In other words, device 10 may be actuated in areverse manner from that described above to achieve a removal of fluidor other substances from the eye. In arrangements in which device 10 ispositioned for removal of fluid or other substances from the eye, one ormore components of device 10 may be reversed (e.g., one-way valve 70 maybe oriented to permit proximal flow of fluid or other substance whilepreventing distal flow of fluid or other substance along piston passage66, etc.). In some embodiments, microcannula 14 may be operably coupledto a suitable vacuum source for the generation of suction.

Device 10 may be comprised of any appropriate materials. For example,microcannula 14 may include one or more of metals (e.g., stainlesssteel, titanium, nitinol, etc.) or a rigid (e.g., sufficiently rigid topush through trabecular meshwork 86 and Schlemm's canal 80 withoutbending or otherwise deforming) polymer (e.g., PEEK, Polyimide, etc.).Exemplary materials also may include polymers transparent to opticalcoherence tomography (OCT) (e.g., glycol modified polyethyleneterephthalate, polyvinal chloride, polymethyl methacrylate, and/orpolyphenylsulfone, etc.) such that imaging via OCT can be donesimultaneously with positioning of microcannula 14 and/or injection of asubstance via orifices 32 while minimally disrupting the images obtainedvia OCT.

Additionally, any one or more portions of microcannula 14, e.g., distalend 30, may be radiopaque to enhance visualization by a medicalprofessional during a procedure. Likewise, handle 12 may include any oneor more metals or polymers, as appropriate. Additionally oralternatively, distal end 30 may include a light-emitting diode (LED)(not shown). When the LED is lit, the medical professional may be ableto see the light through the sclera of the eye, giving the user anindication of the position of microcannula 14 in the eye. In somearrangements, one or more radiopaque indicia or other markings may belocated at distal end 30 of microcannula 14 to facilitate visualizationof the depth of microcannula 14 into the eye of the patient.Additionally, microcannula 14 may include a cutting device (e.g., knife,blade, point tip, etc.) (not shown) adjacent distal end 30. In use, sucha cutting device may enable a medical professional to cut tissue (e.g.,trabecular meshwork 86 and/or Schlemm's canal 80) prior to or followinginjection of a substance via orifices 32. For example, microcannula 14including the cutting device may be moved side-to-side to cut the tissuelifted due to injection of the substance via orifices 32.

While principles of the present disclosure are described herein withreference to illustrative embodiments for particular applications, itshould be understood that the disclosure is not limited thereto. Thosehaving ordinary skill in the art and access to the teachings providedherein will recognize additional modifications, applications,embodiments, and substitution of equivalents all fall within the scopeof the embodiments described herein. Accordingly, the invention is notto be considered as limited by the foregoing description.

A reference to an element in the singular is not intended to mean oneand only one unless specifically so stated, but rather one or more. Forexample, “a” module may refer to one or more modules. An elementproceeded by “a,” “an,” “the,” or “said” does not, without furtherconstraints, preclude the existence of additional same elements.

Headings and subheadings, if any, are used for convenience only and donot limit the invention. The word exemplary is used to mean serving asan example or illustration. To the extent that the term include, have,or the like is used, such term is intended to be inclusive in a mannersimilar to the term comprise as comprise is interpreted when employed asa transitional word in a claim. Relational terms such as first andsecond and the like may be used to distinguish one entity or action fromanother without necessarily requiring or implying any actual suchrelationship or order between such entities or actions.

Phrases such as an aspect, the aspect, another aspect, some aspects, oneor more aspects, an implementation, the implementation, anotherimplementation, some implementations, one or more implementations, anembodiment, the embodiment, another embodiment, some embodiments, one ormore embodiments, a configuration, the configuration, anotherconfiguration, some configurations, one or more configurations, thesubject technology, the disclosure, the present disclosure, othervariations thereof and alike are for convenience and do not imply that adisclosure relating to such phrase(s) is essential to the subjecttechnology or that such disclosure applies to all configurations of thesubject technology. A disclosure relating to such phrase(s) may apply toall configurations, or one or more configurations. A disclosure relatingto such phrase(s) may provide one or more examples. A phrase such as anaspect or some aspects may refer to one or more aspects and vice versa,and this applies similarly to other foregoing phrases.

A phrase “at least one of” preceding a series of items, with the terms“and” or “or” to separate any of the items, modifies the list as awhole, rather than each member of the list. The phrase “at least one of”does not require selection of at least one item; rather, the phraseallows a meaning that includes at least one of any one of the items,and/or at least one of any combination of the items, and/or at least oneof each of the items. By way of example, each of the phrases “at leastone of A, B, and C” or “at least one of A, B, or C” refers to only A,only B, or only C; any combination of A, B, and C; and/or at least oneof each of A, B, and C.

It is understood that the specific order or hierarchy of steps,operations, or processes disclosed is an illustration of exemplaryapproaches. Unless explicitly stated otherwise, it is understood thatthe specific order or hierarchy of steps, operations, or processes maybe performed in different order. Some of the steps, operations, orprocesses may be performed simultaneously. The accompanying methodclaims, if any, present elements of the various steps, operations orprocesses in a sample order, and are not meant to be limited to thespecific order or hierarchy presented. These may be performed in serial,linearly, in parallel or in different order. It should be understoodthat the described instructions, operations, and systems can generallybe integrated together in a single software/hardware product or packagedinto multiple software/hardware products.

In one aspect, a term coupled or the like may refer to being directlycoupled. In another aspect, a term coupled or the like may refer tobeing indirectly coupled.

Terms such as top, bottom, front, rear, side, horizontal, vertical, andthe like refer to an arbitrary frame of reference, rather than to theordinary gravitational frame of reference. Thus, such a term may extendupwardly, downwardly, diagonally, or horizontally in a gravitationalframe of reference.

The disclosure is provided to enable any person skilled in the art topractice the various aspects described herein. In some instances,well-known structures and components are shown in block diagram form inorder to avoid obscuring the concepts of the subject technology. Thedisclosure provides various examples of the subject technology, and thesubject technology is not limited to these examples. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the principles described herein may be applied to otheraspects.

All structural and functional equivalents to the elements of the variousaspects described throughout the disclosure that are known or later cometo be known to those of ordinary skill in the art are expresslyincorporated herein by reference and are intended to be encompassed bythe claims. Moreover, nothing disclosed herein is intended to bededicated to the public regardless of whether such disclosure isexplicitly recited in the claims. No claim element is to be construedunder the provisions of 35 U.S.C. § 112, sixth paragraph, unless theelement is expressly recited using the phrase “means for” or, in thecase of a method claim, the element is recited using the phrase “stepfor”.

The title, background, brief description of the drawings, abstract, anddrawings are hereby incorporated into the disclosure and are provided asillustrative examples of the disclosure, not as restrictivedescriptions. It is submitted with the understanding that they will notbe used to limit the scope or meaning of the claims. In addition, in thedetailed description, it can be seen that the description providesillustrative examples and the various features are grouped together invarious implementations for the purpose of streamlining the disclosure.The method of disclosure is not to be interpreted as reflecting anintention that the claimed subject matter requires more features thanare expressly recited in each claim. Rather, as the claims reflect,inventive subject matter lies in less than all features of a singledisclosed configuration or operation. The claims are hereby incorporatedinto the detailed description, with each claim standing on its own as aseparately claimed subject matter.

The claims are not intended to be limited to the aspects describedherein, but are to be accorded the full scope consistent with thelanguage of the claims and to encompass all legal equivalents.Notwithstanding, none of the claims are intended to embrace subjectmatter that fails to satisfy the requirements of the applicable patentlaw, nor should they be interpreted in such a way.

What is claimed is:
 1. A medical device comprising: a microcannulahaving a proximal end, a distal end, and a cavity, the microcannulahaving a central longitudinal axis; a handle coupled to the proximal endof the microcannula; orifices extending circumferentially about themicrocannula distal end, each of the orifices defining a channelextending transverse to the central longitudinal axis; and one or moregrooves about a circumference of the microcannula.
 2. The medical deviceof claim 1, wherein an outer diameter of the microcannula varies along alength of the microcannula.
 3. The medical device of claim 1, wherein aninner diameter of the microcannula varies along a length of themicrocannula.
 4. The medical device of claim 1, wherein a first orificeamong the orifices is spaced 180 degrees apart from a second orificeamong the orifices.
 5. The medical device of claim 1, wherein each ofthe one or more grooves have a depth between 15 μm and 35 μm.
 6. Themedical device of claim 1, wherein each of the one or more grooves areformed proximal to the orifices.
 7. A medical device comprising: a firstcannula having a distal end, and a cavity, the first cannula having acentral longitudinal axis, and protrusions; the protrusions of the firstcannula extending circumferentially at the distal end of the firstcannula and located in the cavity of the first cannula; a second cannulahaving a distal end, and a cavity, the second cannula moveably housedwithin the first cannula and having a central longitudinal axis,protrusions, and orifices extending circumferentially about the distalend of the second cannula; the protrusions of the second cannulaextending circumferentially at the distal end of the second cannula andlocated on an outer circumferential surface of the second cannula; and afirst orifice among the orifices is positioned parallel to a secondorifice among the orifices.
 8. The medical device of claim 7, whereinthe second cannula includes one or more grooves about a circumference ofthe second cannula.
 9. The medical device of claim 8, wherein the one orgrooves are located at the distal end of the second cannula.
 10. Themedical device of claim 8, wherein the one or more grooves areequidistantly spaced apart.
 11. The medical device of claim 7, whereineach of the protrusions of the first cannula are equidistantly spacedapart.
 12. The medical device of claim 7, wherein each of theprotrusions of the second cannula are equidistantly spaced apart. 13.The medical device of claim 7, wherein the protrusions of the secondcannula are proximal to a user than the protrusions of the first cannulawhen the distal end of the second cannula is within the first cannula.14. The medical device of claim 7, wherein the protrusions of the secondcannula are distal to a user than the protrusions of the second cannulawhen at least a portion of the distal end of the second cannula is movedoutside of the distal end of the first cannula.
 15. A method ofdelivering fluid into the eye, comprising: inserting a microcannulathrough an incision in an anterior chamber of an eye, the microcannulaincluding a proximal end, a distal end, and a cavity, the microcannulahaving a central longitudinal axis; advancing the microcannula distalend through a trabecular meshwork of an eye and into Schlemm's canal ofan eye; and delivering fluid through orifices each of which beingpositioned within Schlemm's canal, each orifice defining a channelextending circumferentially about the microcannula distal end.
 16. Themethod of claim 15, wherein the channel of the orifice of the orificesextends transverse to the central longitudinal axis.
 17. The method ofclaim 15, wherein the microcannula includes one or more grooves about acircumference of the microcannula at the distal end of the microcannula.18. The method of claim 15, wherein the microcannula includes one ormore protrusions extending circumferentially at the distal end of themicrocannula and located on an outer circumferential surface of themicrocannula; and wherein the microcannula is movably housed within asecond cannula, the second cannula having one or more protrusionsextending circumferentially at a distal end of the second cannula andlocated a cavity of the second cannula.
 19. The method of claim 15,wherein the step of advancing the microcannula distal end furthercomprises: applying a force to the microcannula to move the one or moreprotrusions of the microcannula distal to a user and past the one ormore protrusions of the second cannula.
 20. The method of claim 15,wherein delivering fluid through orifices includes delivering fluid intothe Schlemm's canal and one or more layers of the trabecular meshwork.21. A medical device comprising: a microcannula having a proximal end, adistal end, and a cavity, the microcannula having a central longitudinalaxis; a handle coupled to the proximal end of the microcannula; orificesextending circumferentially about the microcannula distal end, each ofthe orifices defining a channel extending transverse to the centrallongitudinal axis; and one or more protrusions about a circumference ofthe microcannula.